1. Field of the Invention
This invention relates to a support ring for handling and testing semiconductor components assembled by the Tape Automated Bonding (TAB) process and, more specifically, to a procedure for attachment thereof to the lead frame.
2. Brief Description of the Prior Art
When semiconductor devices are assembled in strips on lead frames, the lead frames for several devices are generally connected together in a strip with the semiconductor device then being mounted on the lead frames in standard manner. The semiconductor device are then encapsulated with plastic while a plastic support for the leads of the lead frame from each of the dice is simultaneously formed which is spaced from and surrounding each of the device. The lead frames are generally formed of gold plated copper though solder plate or tin plate is also common.
With the continued miniaturization of semiconductor devices, the leads of the lead frame are continually diminished in both width and thickness. Therefore, due to the difference in the coefficients of expansion between the plastic and the lead frame material, the lead portion of the lead frames extending from the device to the support ring have tended to buckle due to the heat applied thereto during the plastic encapsulation and support ring formation. Accordingly, when the semiconductor device fabrication and testing have been completed and the lead frame has been severed between the support ring and the semiconductor device in standard manner, the leads extending from the semiconductor device are out of alignment. This presents an obvious problem for later use of the semiconductor device in placement and attachment on printed circuit boards and the like.